scholarly journals Studies on the sub-units of triose phosphate isomerase

1968 ◽  
Vol 107 (6) ◽  
pp. 737-744 ◽  
Author(s):  
Pamela M. Burton ◽  
S. G. Waley

The sub-unit structure of rabbit muscle triose phosphate isomerase was studied by determination of the number of unique cysteine peptides. Alkylation of the thiol groups with radioactive iodoacetate in the presence of guanidine hydrochloride gave the S-carboxy[14C]methyl derivative of the protein. This was digested with trypsin, and the radioactive peptides were fractionated by ion-exchange chromatography; four main radioactive peaks were obtained, one of which contained two radioactive peptides. Peptide ‘maps’ of the tryptic digest showed five main spots. The relationship between the members of both sets of five peptides was established. The radioactive peptides were characterized, and the results indicated the presence of five unique cysteine residues in the protein. Since there are approximately ten thiol groups/molecule, there are two closely related or identical sub-units. Studies of the terminal residues bear out this suggestion; only one kind of N-terminal residue (alanine) and one kind of C-terminal residue (glutamine) were detected. These results are in accord with the evidence from crystallography.

1974 ◽  
Vol 139 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Anna J. Furth ◽  
J. D. Milman ◽  
J. D. Priddle ◽  
R. E. Offord

1. Triose phosphate isomerase was prepared by chromatography on DEAE-cellulose of an (NH4)2SO4 fraction of an extract of homogenized chicken breast muscle. The product is homogeneous on gel electrophoresis and is suitable for growing crystals for X-ray work. The specific activity is 10000 units/mg and the value for E0.1%280 is 1.20. 2. Comparison between the sum of the amino acid compositions of the tryptic peptides of the protein and the amino acid composition obtained on total hydrolysis of the protein indicates that the relative subunit mass is about 27000. 3. These data, together with the results of the examination of the amino acid compositions of a number of minor peptides, the number of peptides in the tryptic digest and the complete amino acid sequences of the tryptic peptides (the determination of which is described here), give no indication that the subunits are dissimilar. 4. A tentative amino acid sequence is presented for the protein, in which the ordering of the tryptic peptides is derived by homology with the sequence of the rabbit muscle enzyme (Corran & Waley, 1973). 5. An appendix describes the use that was made of mass spectrometry in the determination of some of the sequences. Mass-spectrometric data have been obtained for 35 residues, that is about 15% of the total sequence of the protein. 6. An extended version of the present paper has been deposited as Supplementary Publication SUP 50025 at the British Library, Lending Division (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1973) 131, 5.


1975 ◽  
Vol 145 (2) ◽  
pp. 335-344 ◽  
Author(s):  
P H Corran ◽  
S G Waley

The amino acid sequence of rabbit muscle triose phosphate isomerase was deduced by characterizing peptides that overlap the tryptic peptides. Thiol groups were modified by oxidation, carboxymethylation or aminoen. About 50 peptides that provided information about overlaps were isolated; the peptides were mostly characterized by their compositions and N-terminal residues. The peptide chains contain 248 amino acid residues, and no evidence for dissimilarity of the two subunits that comprise the native enzyme was found. The sequence of the rabbit muscle enzyme may be compared with that of the coelacanth enzyme (Kolb et al., 1974): 84% of the residues are in identical positions. Similarly, comparison of the sequence with that inferred for the chicken enzyme (Furth et al., 1974) shows that 87% of the residues are in identical positions. Limited though these comparisons are, they suggest that triose phosphate isomerase has one of the lowest rates of evolutionary change. An extended version of the present paper has been deposited as Supplementary Publication SUP 50040 (42 pages) at the British Library (Lending Division) (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms given in Biochem. J. (1975) 145, 5.


1974 ◽  
Vol 137 (2) ◽  
pp. 185-197 ◽  
Author(s):  
Edith Kolb ◽  
J. Ieuan Harris ◽  
John Bridgen

The preparation and purification of cyanogen bromide fragments from [14C]carboxymethylated coelacanth triose phosphate isomerase is presented. The automated sequencing of these fragments, the lysine-blocked tryptic peptides derived from them, and also of the intact protein, is described. Combination with results from manual sequence analysis has given the 247-residue amino acid sequence of coelacanth triose phosphate isomerase in 4 months, by using 100mg of enzyme. (Two small adjacent peptides were placed by homology with the rabbit enzyme.) Comparison of this sequence with that of the rabbit muscle enzyme shows that 207 (84%) of the residues are identical. This slow rate of evolutionary change (corresponding to two amino acid substitutions per 100 residues per 100 million years) is similar to that found for glyceraldehyde 3-phosphate dehydrogenase. The reliability of sequence information obtained by automated methods is discussed.


1980 ◽  
Vol 35 (11-12) ◽  
pp. 999-1004 ◽  
Author(s):  
Stefan Zabori ◽  
Rainer Rudolph ◽  
Rainer Jaenicke

The enzymatic activity and quaternary structure of rabbit muscle triose phosphate isomerase remains unchanged in the concentration range from 2 μg/ml to 2 ng/ml. In this concentration range the enzyme can be reactivated after dissociation and denaturation in 6.5 ᴍ guanidine hydrochloride. Removal of the denaturant by dilution and separation of inactive wrong aggregates (5-20%) lead back to active dimers, indistinguishable from the native enzyme as far as enzymatic and physicochemical properties are concerned. Based on the long term stability of the enzyme, the reactivation kinetics were analyzed at low concentrations and 0 °C, conditions where the association of inactive monomers to active dimers is predominant in the process of reactivation. The concentration dependence of the rate of reactivation and the kinetic profiles could be described by a consecutive first-order folding and second-order association reaction scheme with the rate constants kuni = 1.9 × 10-2 s-1 and kbi = 3 × 105 ᴍ-1 · s-1. This implies that the folded monomers of triose phosphate isomerase, which are intermediate states during reconstitution, cannot possess appreciable enzymatic activity.


Triose phosphate isomerase is a dimeric enzyme of molecular mass 56000 which catalyses the interconversion of dihydroxyacetone phosphate (DHAP) and D-glyceraldehyde-3-phosphate. The crystal structure of the enzyme from chicken muscle has been determined at a resolution of 2.5 A, and an independent determination of the structure of the yeast enzyme has just been completed at 3 A resolution. The conformation of the polypeptide chain is essentially identical in the two structures, and consists of an inner cylinder of eight strands of parallel |3-pleated sheet, with mostly helical segments connecting each strand. The active site is a pocket containing glutamic acid 165, which is believed to act as a base in the reaction. Crystallographic studies of the binding of DHAP to both the chicken and the yeast enzymes reveal a common mode of binding and suggest a mechanism for catalysis involving polarization of the substrate carbonyl group.


1974 ◽  
Vol 141 (3) ◽  
pp. 753-760 ◽  
Author(s):  
Christopher A. Browne ◽  
Stephen G. Waley

The3H–H exchange of chicken muscle and rabbit muscle triose phosphate isomerases was studied. Their behaviour was mostly very similar. ‘Exchange-in’ (acquisition of radioactivity when protein was incubated in3H2O) was measured at 37°C and at pH7.5, and the rates of exchange of the native and liganded enzymes were compared. Inhibitors and substrates retarded exchange, substrates showing the most marked effect; structural rearrangements in the enzyme may thus play some part in catalysis. The inhibitor phosphoglycollate affected the rabbit enzyme, but had little or no effect on the chicken enzyme. ‘Exchange-out’ (loss of radioactivity from protein previously labelled by incubation in3H2O) was measured by hollow-fibre dialysis. When ligand was removed during the course of dialysis (by replacing buffer that contained ligand with buffer that lacked ligand) there was a prompt decrease in the number of labelled H atoms of the protein. Analysis of the curves provides some information about the number and half-lives of the responsive H atoms. Ligands decrease the motility of the protein and affect about one-fifth of the chain. Low concentrations of glycerol 3-phosphate have an effect that is greater than expected.


1976 ◽  
Vol 153 (3) ◽  
pp. 741-744 ◽  
Author(s):  
M K Thomas ◽  
T G Spring

2-Phosphotartronate has been synthesized by permanganate oxidation of glycerol 2-phosphate and has been tested as an inhibitor of five glycolytic enzymes that bind phosphoglycerate or phosphoglycollate. Competitive inhibition of rabbit muscle phosphoglycerate mutase, enolase and pyruvate kinase was observed. Triose phosphate isomerase and 3-phosphoglycerate kinase were not inhibited.


1971 ◽  
Vol 122 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Janet C. Miller ◽  
S. G. Waley

1. The nature of the subunits in rabbit muscle triose phosphate isomerase has been investigated. 2. Amino acid analyses show that there are five cysteine residues and two methionine residues/subunit. 3. The amino acid sequences around the cysteine residues have been determined; these account for about 75 residues. 4. Cleavage at the methionine residues with cyanogen bromide gave three fragments. 5. These results show that the subunits correspond to polypeptide chains, containing about 230 amino acid residues. The chains in triose phosphate isomerase seem to be shorter than those of other glycolytic enzymes.


1974 ◽  
Vol 139 (1) ◽  
pp. 1-10 ◽  
Author(s):  
P. H. Corran ◽  
S. G. Waley

1. The peptides obtained by tryptic digestion of S-[14C]carboxymethylated rabbit muscle triose phosphate isomerase have been studied. 2. The first step in the fractionation of the tryptic digest was gel filtration on coupled columns of Sephadex G-25 and G-50. Further fractionation was carried out by paper electrophoresis and paper chromatography. 3. The digest contained 26 peptides and three free amino acids. The sizes of the peptides ranged from two to 29 residues. 4. The sequences of the peptides have been determined. 5. The length of the polypeptide chains is about 250 amino acid residues. 6. The variant sequences encountered were due to partial deamidation; this may be one of the reasons for multiple forms of the enzyme. 7. The chicken and rabbit enzymes are compared. 8. Detailed evidence for the sequences of the tryptic peptides has been deposited as Supplementary Publication SUP 50024 at the British Library, Lending Division (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms given in Biochem. J. (1973) 131, 5.


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